Christopher S Chase

US Patent:

8248921, Aug 21, 2012

Filed:

Nov 3, 2006

Appl. No.:

11/592706

Inventors:

Chin Yuan - San Ramon CA, US
Kuo-Hui Liu - San Ramon CA, US
Christopher Chase - Austin TX, US

Assignee:

AT&T Intellectual Property I, L.P. - Atlanta GA

International Classification:

G01R 31/08

US Classification:

370222

Abstract:

A method is disclosed that includes receiving a data packet at a first video distribution hub via a first link. The method also includes determining whether a second link has failed, wherein the first video distribution hub communicates with a second video distribution hub via a primary network path that includes the second link. When the second link has failed, a backup network path to send the data packet, or a copy thereof, to the second video distribution hub, is determined based on data stored at the first video distribution hub. The method also includes sending the data packet, or the copy thereof, to the second video distribution hub via the backup network path, wherein the backup network path does not include the second link.

US Patent:

8488646, Jul 16, 2013

Filed:

Aug 23, 2012

Appl. No.:

13/593375

Inventors:

Connie Chang-Hasnain - Palo Alto CA, US
Christopher Chase - Kensington CA, US

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

H01S 5/00

US Classification:

372 5011, 372 4501, 372 501, 372 50124, 359558, 359563, 359566, 359569, 359572, 359573, 359575

Abstract:

Enhanced reflectivity High-Contrast Gratings are described which operate in different medium. An HCG is described with a deep/buried metallization layer separated at a distance of least three to four grating thicknesses from the grating. Reflective bandwidth of the HCG is substantially increased, such as by a factor or five, by inclusion of the deep/buried metallization layer. An HCG is described which provides high reflectivity, even when embedded into materials of a moderate to high index of refraction, such as semiconductor material. Vertical cavity surface emitting laser embodiments are described which utilize these reflectivity enhancements, and preferably utilize HCG reflectors for top and/or bottom mirrors.

US Patent:

8526471, Sep 3, 2013

Filed:

Aug 23, 2012

Appl. No.:

13/593407

Inventors:

Connie Chang-Hasnain - Palo Alto CA, US
Weijian Yang - Berkeley CA, US
Christopher Chase - Kensington CA, US
Forrest G. Sedgwick - Berkley CA, US

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

H01S 3/113
H01S 3/098
G02B 5/18

US Classification:

372 11, 372 18, 359572

Abstract:

A saturable absorber (SA) based on a high-contrast grating (HCG) having a buried layer of quantum structures for absorption, and which is particularly well suited for use in a mode-locked application. The HCG-SA provides three times the bandwidth compared with traditional DBR structures, while exhibiting a lower saturation fluence due to the field enhancement inside the grating. Varying grating bar width over one or two axis provides lensing effects on the optical output, while chirping of the period and duty cycle changes optical phase relationships. Novel VCSEL embodiments with external or internal cavities are described using the HCG-SA.

US Patent:

8553535, Oct 8, 2013

Filed:

Jul 2, 2012

Appl. No.:

13/540150

Inventors:

Chin Yuan - San Ramon CA, US
Kuo-Hui Liu - San Ramon CA, US
Christopher Chase - Austin TX, US

Assignee:

AT&T Intellectual Property I, L.P. - Atlanta GA

International Classification:

G01R 31/08

US Classification:

370222

Abstract:

A method includes sending a data packet, or a copy of the data packet, from a first video distribution hub to a second video distribution hub. The first video distribution hub is coupled to a first link and to a second link. The method also includes, in response to the second link being intact, sending the data packet, or the copy of the data packet, from the first video distribution hub to the second video distribution hub via a primary network path that includes the second link and excludes the first link. The method also includes, in response to a failure of the second link, sending the data packet, or the copy of the data packet, from the first video distribution hub to the second video distribution hub via a backup network path that includes the first link and that does not include the second link.

US Patent:

20110280269, Nov 17, 2011

Filed:

May 13, 2010

Appl. No.:

12/779248

Inventors:

Connie Chang-Hasnain - Palo Alto CA, US
Christopher Chase - Kensington CA, US
Yi Rao - Berkeley CA, US

Assignee:

THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA

International Classification:

H01S 5/026

US Classification:

372 501

Abstract:

A Vertical Cavity Surface Emitting Laser (VCSEL) and its fabrication are taught which incorporate a high contrast grating (HCG) to replace the top mirror of the device and which can operate at long-wavelengths, such as beyond 0.85 μm. The HCG beneficially provides a high degree of polarization differentiation and provides optical containment in response to lensing by the HCG. The device incorporates a quantum well active layer, a tunnel junction, and control of aperture width using ion implantation. A tunable VCSEL is taught which controls output wavelength in response to controlling a micro-mechanical actuator coupled to a HCG top mirror which can be moved to, or from, the body of the VCSEL. A fabrication process for the VCSEL includes patterning the HCG using a wet etching process, and highly anisotropic wet etching while precisely controlling temperature and PH.

US Patent:

20130058370, Mar 7, 2013

Filed:

Aug 23, 2012

Appl. No.:

13/593382

Inventors:

Connie Chang-Hasnain - Palo Alto CA, US
Christopher Chase - Kensington CA, US
Fanglu Lu - Berkeley CA, US
Forrest G. Sedgwick - Berkeley CA, US
Igor Karagodsky - Brighton MA, US

Assignee:

THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA

International Classification:

H01S 5/187
G02B 5/18

US Classification:

372 5011, 359573, 359572

Abstract:

Planar lenses and reflectors are described comprising subwavelength high-contrast gratings (HCG) having high index of refraction grating elements spaced apart from one another in straight and/or curved segments and surrounded by low index material. The high-contrast grating is configured to receive an incident wave which excites multiple modes within the high-contrast grating and is focused for reflection and/or transmission by said high contrast grating. The width of the high contrast grating bars vary along a distribution direction of the grating bars which is perpendicular to the length of the grating bars and/or varies along the length of one or more grating bars to focus said reflection and/or transmission. The HCG is configured to provide double focusing, whose use is exemplified within a vertical cavity surface emitting laser (VCSEL) structure using focusing HCG structures for both the top and bottom mirrors.

US Patent:

20150288146, Oct 8, 2015

Filed:

Oct 16, 2013

Appl. No.:

14/055058

Inventors:

- Oakland CA, US
Christopher Chase - Kensington CA, US
Yi Rao - Albany CA, US

Assignee:

THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA

International Classification:

H01S 5/183
H01S 5/40
H01S 5/20
H01S 5/187
H01S 5/02

Abstract:

A surface emitting laser apparatus is formed using a patterned silicon-on-insulator (SOI)-like substrate which is patterned with a buried sub-wavelength high contrast grating and adapted for bonding of a half-VCSEL device containing at least an active region and an upper mirror, to create a VCSEL. The wavelength of the VCSEL, or any individual VCSEL within an array of VCSEL devices, can be set in response to changing HCG characteristics of the lower mirror in the SOI-like substrate, or in the region above the lower mirror within the half-VCSEL. The inventive VCSEL device and fabrication method are beneficial for a number of application and devices.

US Patent:

20140353530, Dec 4, 2014

Filed:

May 29, 2014

Appl. No.:

14/290607

Inventors:

- Oakland CA, US
- San Jose CA, US
Weijian Yang - Berekely CA, US
Christopher Chase - Kensington CA, US
Yi Rao - Albany CA, US
Michael Chung-Yi Huang - North Caldwell NJ, US

Assignee:

BANDWIDTH10, INC. - San Jose CA
THE REGENTS OF THE UNIVERSITY OF CALIFORNIA - Oakland CA

International Classification:

G01J 1/08

US Classification:

250552

Abstract:

A dual usage HCG VCSEL detector is provided with a high contrast grating (HCG) reflector first reflector that has a two dimensional periodic structure. The two dimensional structure is a periodic structure that is a symmetric structure with periodic repeating. The symmetrical structure provides that polarization modes of light are undistinguishable. A second reflector is in an opposing relationship to the first reflector. A tunable optical cavity is between the first and second reflectors. An active region is positioned in the cavity between the first and second reflectors. The photodetector is polarization independent. An MQW light absorber is included converts light to electrons. A dual usage HCG VCSEL-detector includes a high contrast grating (HCG) reflector first reflector, and a second reflector in an opposing relationship to the first reflector. A tunable optical cavity is between the first and second reflectors. An active region is positioned in the cavity between the first and second reflectors. The dual usage HCG VCSEL-detector that operates as a dual usage HCG VCSEL and as a tunable photodetector.